Math in the public sphere

Wore my New York City Math Team 2007 t-shirt to the supermarket yesterday; the cashier was very impressed that I knew 32 × 32 immediately.  In a pleasant detour from how these conversations usually go, he remarked that he needs pencil and paper to work problems like that out.  This reminded me of a joke told by my grad school colleague Nick:

A mathematician and a prostitute are at a party.  The prostitute asks the mathematician what he does for a living.  He replies, “I’m a mathematician; and yourself?”  The prostitute responds, “I’m a sex worker.”  “Ah,” says the mathematician, “sex.  I was never very good at that.”

“My brain is open” by Bruce Schechter

My Brain Is Open is one of two biographies of Paul Erdős that I know of, the other being Hoffman’s The Man Who Loved Only Numbers. I mostly enjoyed this one; it conveyed a good sense of the subject’s eccentricities as a person but also, more importantly, his significance in building and binding together a clan of mathematicians (many, but not all, Hungarian) working on problems in entirely new branches of mathematics.  (Generally I think all combinatorialists, even those of us not working in “Hungarian combinatorics,” owe Erdős a debt of gratitude for helping make our field a respectable area of study.)

Ken Appel has died

The Times has a very nice obituary of Kenneth Appel, the main mastermind behind the proof of the four-color theorem, one of the crowning achievements of graph theory. He also sounds likfair pleasant, interesting man. The advent of computers has revolutionized the practice of mathematics (there is hardly a problem I try to solve without extensive computer exploration), and Appel was a pioneer in using artificial computation to make the intractable, tractable.

Today’s signs of Spring

• Sunshine
• Birds chirping
• First farmers market of the year (essentially a petting zoo)
• All the bike racks at the math department filled up in the morning
• Only one day in the next week has snow in the forecast
• Undergrads wearing flip-flops
• A swarm of six or more tow trucks clearing my street so the first street sweeper of the year could come through

On the meaning of words

An event center (I guess that means you can rent out their space for large events?) near my apartment has as its tagline the phrase “Beyond ordinary, extraordinary.”

Spring break in Minnesota

This gallery contains 17 photos.

On Monday, it was 29 degrees Fahrenheit out when I left for work in the morning; perhaps two inches of snow had fallen the night before.  It got steadily colder all day.  Tuesday night, the low was 1 degree.  I … Continue reading →

Iraq

My students were early in elementary school when the US invaded Iraq.  I worry quite a bit that they have no sense of what an abomination it was, and how massively our political elites betrayed us.